'\" t
.\" Copyright (c) Bruno Haible <haible@clisp.cons.org>
.\"
.\" SPDX-License-Identifier: GPL-2.0-or-later
.\"
.\" References consulted:
.\"   GNU glibc-2 source code and manual
.\"   Dinkumware C library reference http://www.dinkumware.com/
.\"   OpenGroup's Single UNIX specification http://www.UNIX-systems.org/online.html
.\"   ISO/IEC 9899:1999
.\"
.TH iswblank 3 2024-06-15 "Linux man-pages 6.9.1"
.SH NAME
iswblank \- test for whitespace wide character
.SH LIBRARY
Standard C library
.RI ( libc ", " \-lc )
.SH SYNOPSIS
.nf
.B #include <wctype.h>
.P
.BI "int iswblank(wint_t " wc );
.fi
.P
.RS -4
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.RE
.P
.BR iswblank ():
.nf
    _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
.fi
.SH DESCRIPTION
The
.BR iswblank ()
function is the wide-character equivalent of the
.BR isblank (3)
function.
It tests whether \fIwc\fP is a wide character
belonging to the wide-character class "blank".
.P
The wide-character class "blank" is a subclass of the wide-character class
"space".
.P
Being a subclass of the wide-character class "space",
the wide-character class "blank" is disjoint from the
wide-character class "graph" and therefore also disjoint
from its subclasses "alnum", "alpha", "upper", "lower", "digit",
"xdigit", "punct".
.P
The wide-character class "blank" always contains
at least the space character
and the control character \[aq]\[rs]t\[aq].
.SH RETURN VALUE
The
.BR iswblank ()
function returns nonzero
if \fIwc\fP is a wide character
belonging to the wide-character class "blank".
Otherwise, it returns zero.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lbx lb lb
l l l.
Interface	Attribute	Value
T{
.na
.nh
.BR iswblank ()
T}	Thread safety	MT-Safe locale
.TE
.SH STANDARDS
POSIX.1-2008.
.SH HISTORY
POSIX.1-2001.
.SH NOTES
The behavior of
.BR iswblank ()
depends on the
.B LC_CTYPE
category of the
current locale.
.SH SEE ALSO
.BR isblank (3),
.BR iswctype (3)
